Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Improve daisy download speed by multi-thread tool"
  - Improve daisy download speed by multi-thread tool

    Use multi-thread tool such as aria2c to download the daisy image,
    to reduce the time spent on downloading.

    Change-Id: Id1b7f9195fe0d499b9b02b0a8410e02871f675f9
    Signed-off-by: Alex Yang <yangyang1@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 87bdf55..29e0b0e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 87bdf551e4449d6650712702c0cbe1595b33d5c8
+Subproject commit 29e0b0ea6b5555045a7aad07d6c070967fbee355